The cities you mention all have their attractions, but Vienna has one great advantage and one sort of major disadvantage.

The disadvantage is that it can be quite cold in the middle of winter in Vienna.
A reference book will give you average temperatures, but I believe that it's often in the twenties F -- though the snow can make the city look nice.

The advantage is that Viennese cultural and social life is in full swing in mid-winter. The famous orchestras and operas have full schedules, there are several traditional Christmas fairs, and there are many society and government-sponsored balls (some of the latter are hard to get into.)

So if you can stand the weather, the argument for Vienna would be that there are attractions there which are at their best in the winter. (And remember that Vienna's old part is so concentrated, the metro and trams so good, and the taxis so reliable that you don't need to spend a lot of time actually outside.)

Also in my experience Vienna has more reasonably priced hotels than Paris.